One method for increasing filtration efficiency of gasoline engine exhaust particulate filters includes integrating a membrane layer on the surface of the particulate filter substrate to elevate filtration efficiency while reducing a pressure drop across the filter, and using a high-porosity filter substrate combined with a surface wash coat. However, filters with an integrated membrane layer increase manufacturing costs. Furthermore, high-porosity substrates with surface wash coats may only marginally increase filtration efficiency, dependent on the wash coat amount. Further still, substrates that are heavily loaded with wash coat can exhibit increased filtration efficiency, but only at drastically high filtration back pressures, which can render the filter inoperable.
The inventors herein have recognized the above issues, and have developed systems and methods to at least partially address them. In one example, a method for a vehicle may comprise, responsive to installation of a new exhaust particulate filter, doping fuel with an ash-producing additive, and combusting the doped fuel to produce ash, wherein the ash deposits as an ash coating on the new exhaust particulate filter.
In another example, a method for a new gasoline engine may comprise, installing an exhaust particulate filter, doping gasoline with an ash-producing additive, and combusting the doped gasoline to produce ash, wherein the ash deposits as an ash coating on the exhaust particulate filter.
In another example, a vehicle system may comprise: a combustion engine; a fuel tank; an exhaust particulate filter receiving exhaust from the combustion engine; and a controller with computer readable instructions stored on non-transitory memory for, responsive to installation of a new exhaust particulate filter, doping fuel with an ash-producing additive, and combusting the doped fuel to produce ash, wherein the ash deposits as an ash coating on the new exhaust particulate filter.
In this way, combusting the doped fuel achieves the technical result of producing an ash coating on the new exhaust particulate filter, which can increase the clean filtration efficiency of the filter at mileage levels significantly less than 3000 miles without a membrane, while maintaining filtration back pressure levels.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.